Drum brakes on rear axles of at least large motor vehicles comprise a brake cylinder, a brake lever arm connected to the brake cylinder, and an eccentric shaft connected to the brake lever arm and provided with an S cam, whereby during braking the braking force is arranged to be transmitted from the brake cylinder to the brake lever arm, which rotates the eccentric shaft so that the S cam turns and thereby pushes out the brake shoes which then press upon the brake drum to brake the vehicle.
In prior art the drum brake is installed close to the rear axle via a bearing bracket which is fastened to the rear axle and configured to journalling the eccentric shaft and serving as a mounting for the brake cylinder.
Assembly involves first fastening the bearing bracket to the rear axle and then fitting the other parts by successively connecting the eccentric shaft to the bearing bracket, the brake lever arm to the eccentric shaft and the brake cylinder to the bearing bracket.
Such fastening by means of the bearing bracket results in inefficient fitting of the drum brake to the rear axle, inter alia because of limited accessibility and limited scope for preassembly.